The rTRIPLEX-CW-Flux R package

Shulan Sun, Wenhua Xiang

2022-10-11

Abstract

This vignette provides an overview of the rTRIPLEXCWFlux R package functions. We provide a working examples to demonstrates the basic functionality and use of the package.

Purpose

The rTRIPLEXCWFlux package integrated the carbon uptake submodule and evapotranspiration submodule of the TRIPLEX-CW-Flux model to run the simulation of carbon-water coupling. In the R script, the user only needs to download and load the rTRIPLEX-CW-Flux package, and then input the variables and parameters of the model to obtain simulated results. This package accelerates the running speed of the model and facilitates the estimation of carbon sequestration and water consumption in different forest ecosystems using extensive flux observed data.

Model run

To display the basic functionality of rTRIPLEXCWFlux R package, a simple simulation will be performed using TRIPLEX-CW-Flux model. The function of run TRIPLEX-CW-Flux from R is TRIPLEX_CW_Flux. After called, the function will run and return the charts of simulated result for NEP and ET at 30 min scale, and monthly variation of the input environmental factors.

Before running the rTRIPLEXCWFlux R package, users need to prepare the input variables and parameters required by the model, and check whether the column name is consistent with that in internal data in advance. You can use data("Inputpara") and data("Inputvariable") to see the information and format of input variables and parameters tables, respectively.

In this example, we run a simulation for a Chinese fir plantation. The input data are provided as internal data in rTRIPLEXCWFlux.

library(rTRIPLEXCWFlux)
out<-TRIPLEX_CW_Flux (Input_variable=Inputvariable,
                 Input_parameter=Inputpara)
head(out)
#>            DATE Vms   Ta RH VPDhpa SVWC30cm   Rn PPFD Rainfall Month Day year
#> 1 2019/1/1 0:00 0.2 -1.4 88    0.7    26.70 -0.3    0        0     1   1 2019
#> 2 2019/1/1 0:30 0.3 -1.4 89    0.6    26.70 -0.2    0        0     1   1 2019
#> 3 2019/1/1 1:00 0.6 -1.4 93    0.4    26.70 -0.2    0        0     1   1 2019
#> 4 2019/1/1 1:30 0.5 -1.5 96    0.2    26.75 -0.4    0        0     1   1 2019
#> 5 2019/1/1 2:00 0.7 -1.4 96    0.2    26.80 -0.3    0        0     1   1 2019
#> 6 2019/1/1 2:30 0.6 -1.5 99    0.0    26.80 -0.2    0        0     1   1 2019
#>   time DOY      Cof         G        NEE        LE season seasonnum
#> 1  0.0   1 389.9701 -31.73333 0.05943252 31.390369 Winter         4
#> 2  0.5   1 389.9273 -31.46667 0.04466091 19.896811 Winter         4
#> 3  1.0   1 391.0606 -31.43333 0.04414407 19.870601 Winter         4
#> 4  1.5   1 391.1129 -31.40000 0.04466091 19.735104 Winter         4
#> 5  2.0   1 391.2121 -31.33333 0.01363915  0.980239 Winter         4
#> 6  2.5   1 390.1345 -31.33333 0.01523203 12.144469 Winter         4
#>   ObserveNEE30         OETS    NEP30min         ETS GPP30min    Re30min
#> 1 -0.029175966 0.0225796146 -0.02841504 0.003038809        0 0.02841504
#> 2 -0.021924448 0.0143121074 -0.02841504 0.002373832        0 0.02841504
#> 3 -0.021670725 0.0142932538 -0.02841504 0.001446595        0 0.02841504
#> 4 -0.021924448 0.0141944495 -0.02827368 0.001315828        0 0.02827368
#> 5 -0.006695583 0.0007051022 -0.02841504 0.001058497        0 0.02841504
#> 6 -0.007477542 0.0087348946 -0.02827368 0.000898963        0 0.02827368

The output of the TRIPLEX_CW_Flux function are a long format dataframe and charts of simulated result for net ecosystem productivity (NEP) and evapotranspiration (ET) at 30 min scale, and monthly variation of the input environmental factors. The first 18 columns of the dataframe are input variables. The nineteenth and twentieth columns are season and the number of seasons. The twenty-first and twenty-second columns are the observed NEP and ET after the conversion unit. The twenty-third column is the simulated net ecosystem productivity, the twenty-fourth column is the simulated ET, the twenty-fifth column is the estimated gross ecosystem productivity, and the twenty-sixth column is the estimated ecosystem respiration.
i. the graph of Simulated ET results at 30 min scale in four seasons.
ii. the graph of Simulated NEP results at 30 min scale in four seasons.
iii. the graph of Simulated NEP and ET at 30 min scale during whole studied period.
iv. the graph of diurnal dynamics for observed and simulated NEP at 30 min scale during whole studied period.
v. the graph of diurnal dynamics for observed and simulated ET at 30 min scale during whole studied period.
vi. the graph of environmental factors during whole studied period.